Diagnosis and histopathological study of avian influenza virus-H5 (AIV-H5) in broiler farms

Abstract

This study was conducted for diagnosis and description of the pathological changes of AIV-H5 as the causative pathogen in Iraqi broiler farms. The current study was carried out on 84 broiler farms. Infected birds were tested for detection of the AIV infection from the tracheal swabs by rapid chromatographic AIV type A and H5 test kits. In RRT-PCR 8 samples (8 farms) of Trachea were selected to be tested by this assay. Samples of trachea, lung, and spleen from the dead birds with natural AIV-H5 infection were submitted for histopathological examination. seventy-two out of 84 farms tested for AIV-Type A gave positive results, and 58 out of 72 positives for type A-AIV gave a positive result for H5 antigen in a rapid chromatographic strip. The main gross lesions in the trachea of infected birds were severe congestion and hemorrhage. In the RRT-PCR assay, 8 out of 8 samples gave a distinct positive result for this test. The microscopic histopathological examination of infected tracheas showed obvious desquamation of lining epithelium with complete loss of cilia associated with congestion of blood vessels in lamina properia. Infected lungs revealed diffuse alveolar damage and severe multifocal vascular congestion. There was deposition of fibrinous material in the splenic tissue associated with the disappearance of the germinal centers. Thus, we concluded that AIV-H5 infection causes severe pathological and histopathological changes as a result of systemic infection. The RRT-PCR assay was highly sensitive and specific for the detection of highly pathogenic avian influenza virus subtypes.

Pathological and Molecular Characterization of H5 Avian Influenza Virus in Poultry Flocks from Egypt over a Ten-Year Period (2009–2019)

“…Pneumonic areas with intense aggregation of leukocytes and vasculitis of the pulmonary blood vessels were also detected in lung. These present histopathological findings are consistent with several previous pathological data reported with HPAI in the literature [ 42 , 44 , 48 , 51 , 52 , 53 ]. In these previous studies [ 42 , 44 , 48 , 51 , 52 , 53 ], trachea and lungs showed congestion, edema, thrombosis, diffuse hemorrhages, necrosis, and sloughing of the epithelial lining of trachea and bronchi, extensive alveolar damage, together with inflammatory cells infiltration including macrophages, lymphocytes, and heterophils.…”

“…These present histopathological findings are consistent with several previous pathological data reported with HPAI in the literature [ 42 , 44 , 48 , 51 , 52 , 53 ]. In these previous studies [ 42 , 44 , 48 , 51 , 52 , 53 ], trachea and lungs showed congestion, edema, thrombosis, diffuse hemorrhages, necrosis, and sloughing of the epithelial lining of trachea and bronchi, extensive alveolar damage, together with inflammatory cells infiltration including macrophages, lymphocytes, and heterophils. In addition, depletion of the lymphoid follicles and heterophilic cells infiltration was observed in the spleen, together with hemorrhagic foci and necrosis of the periellipsoid lymphocyte sheaths, which is consistent with several previous studies [ 43 , 48 , 51 ].…”

“…In addition, depletion of the lymphoid follicles and heterophilic cells infiltration was observed in the spleen, together with hemorrhagic foci and necrosis of the periellipsoid lymphocyte sheaths, which is consistent with several previous studies [ 43 , 48 , 51 ]. Regarding the liver, it showed multiple necrotic foci with leukocytic infiltration, which is in agreement with several previous reports where the liver showed severe congestion, hemorrhage, multifocal hepatic necrosis with fragmented nuclei of the hepatocytes, and infiltration of lymphocytes and macrophages in the periphery of portal triades [ 48 , 51 , 52 , 54 ]. Furthermore, the pancreas showed multifocal necrosis with vacuolation of acinar epithelium and infiltration of the mononuclear cells in the parenchyma, as reported elsewhere [ 48 , 51 , 55 ].…”

“…Furthermore, the pancreas showed multifocal necrosis with vacuolation of acinar epithelium and infiltration of the mononuclear cells in the parenchyma, as reported elsewhere [ 48 , 51 , 55 ]. Collectively, our present histopathological data have coincided with several previous findings in lung, spleen, liver, and pancreas HPAI as a result of infection [ 42 , 44 , 48 , 51 , 52 ]. Despite this similarity between the reported pathological changes of AIV H5 infected birds versus previous reports, none of these signs are considered pathognomonic for the disease [ 40 , 56 , 57 , 58 ].…”

Epidemiological and molecular study of Rotavirus infection among human and animal in Karbala and Basrah provinces

“…Therefor recognizing vp7gene (glycoprotein) according to its function in infection and pathogenesis as outer capsid protein for neutralization antibody and enter to host cell in replication cycle (21). While (22,23) showed RT-PCR less efficiency than RT-qPCR for amplification in comparison with +ve and -ve control. The present study was designed to explore the role of group A rotavirus as causative agents of diarrhea by using PCR assay as more sensitive technique, in Basrah and Karbala provinces.…”